Crushed rock has played and continues to play an integral role in road building and road maintenance. Traditionally, rock is extracted from rock quarries, located on selected property sites and transported to a nearby fixed-base rock crushing plant. Current rock crushing plants typically consist of multiple rock crushers that reduce oversized rock down to a desired size, multiple screens that separate the crushed rock according to size and multiple conveyors that transport the sorted material between the rock crushers and screens and then onto size designated stockpiles. Transfer of rock from the screens to the stockpiles can also be accomplished through the use of front end loaders, dump trucks and the like.
Prior art rock crushing facilities are typically set up near the rock extraction location such that great time, energy and manpower is required to properly position, secure and interconnect the plant components. The rock crushed by these plants is stockpiled and used to serve the needs of a regional area. Since crushed rock is hauled from the fixed base rock crushing plant to the point of use, the service area is limited to a certain radius by economics and efficiency reasons. As a result, multiple rock quarries and rock crushing plants are selectively spaced apart so as to enable the plants to supply crushed rock to distinct regional areas.
This practice requires equipping and manning multiple fixed rock crushing plants, which in itself is expensive and inefficient, but previously considered unavoidable. A single plant typically requires, e.g., three rock crushers, two screens, about a half dozen feed conveyors and similar number of stockpile conveyors. This equipment has to be organized into a desired pattern or arrangement to enable the rock materials to be sequenced through the equipment for processing. Given the number of processing stages, breaking down the entire operation presents an ominous task to an operator desiring to move the operation between job sites. To break down, move and bring back on line the current operating systems can take a number of days and many man-hours, the cost can be prohibitive and is considered viable only when moving from one permanent job site to another permanent job site.
Factors affecting the immobility of these crushing plants include the need to disassemble the various processing stages and to rearrange the equipment into small enough components such that when loaded onto trailers, they meet height, weight, width and length road restrictions. Any connection between the major processing components (e.g. feed conveyors and the like) need to be decoupled and moved separately.
Nevertheless, the preferred embodiment of the present invention resolves the inefficiencies and exorbitant costs associated with the current practice by converting a fully operable, permanently sited rock crushing plant as generally described above into a mobile rock crushing plant.